Some gals keep it low key when it comes to maternity clothes, but not Petra Ecclestone!

Petra showed off her growing baby bump in a snakeskin dress last night, and while the family was celebrating her 24th birthday at Giorgio Baldi, Tamara wasn't about to be outdone by her little sister! The busty brunette heiress also had some curves to show off, and um, wow. What else can we say? Girlfriend certainly knows how to render us speechless!